Ultrasonic vibrator capable of infallibly preventing drops of water from entering the inside of a casing of the vibrator even if autoclave sterilization without a drying process is performed

ABSTRACT

An ultrasonic vibrator has a very versatile, simple structure without a rotational structure. In order to infallibly prevent drops of water from entering the inside of the casing of the vibrator even if autoclave sterilization is performed without a drying process, the ultrasonic vibrator has a connecting member and a partition member, each used as a barrier plate member making up the inside of the vibrator body. The ultrasonic vibrator additionally has O-rings disposed in a packing,, an electrode, and an airtight cap. By the O-rings, water is prevented from entering a lumen of a transducer. The electrode is insulated by a sealing agent, and a short circuit is presented.

RELATED APPLICATIONS

[0001] This is a division of U.S. patent application Ser. No.09/587,847, filed Jun. 6, 2000, in the name of Norikiyo Shibata andentitled Ultrasonic Vibrator Capable of Infallibly Preventing Drops ofWater From Entering the Inside of a Casing of the Vibrator Even ifAutoclave Sterilization Without a Drying Process is Performed.

[0002] This application claims benefit of Japanese Application No. Hei11-161393 filed in Japan on Jun. 8, 1999, and Japanese Application No.Hei 11-196511 filed in Japan on Jul. 9, 1999, the contents of which arehereby incorporated by reference.

BACKGROUND OF THE INVENTION

[0003] 1. Field of the Invention

[0004] This invention relates to an ultrasonic vibrator for generatingultrasonic vibrations by supplying a high frequency current to avibrating element.

[0005] 2Description of Related Art

[0006] Recently, the use of an ultrasonic surgical apparatus, whichcomprises an ultrasonic vibrator, by which various surgical operationsare performed, such as destruction of a calculus or removal of a tumor,has come into practical use. The ultrasonic surgical apparatus comprisesa handpiece in which the ultrasonic vibrator is incorporated, and adriving power supply unit that is connected to the handpiece andsupplies a driving current to the ultrasonic vibrator.

[0007] The ultrasonic surgical apparatus for surgical operations can beused in an abdominal operation or a laparoscopic operation generally byattaching various probes to a device (i.e., vibrator) that receives ahigh frequency current from a power-supply unit, and generatesultrasonic vibrations.

[0008] This type of surgical apparatus must be sterilized because it ishandled by a surgeon directly with his/her hand. The vibrator of theultrasonic surgical apparatus must also be subjected to autoclavesterilization.

[0009] Such a vibrator is disclosed in, for example, U.S. Pat. No.5,395,240, Japanese Patent Publication No. Hei 7-106206, and JapaneseLaid-open Patent Publication No. Hei 10-127655.

[0010] There are many kinds of autoclave sterilization methods, eachdetermined by a combination of parameters of time, pressure,temperature, etc., in a vacuum drawing step, a sterilizing step, adrying step, and so on.

[0011] The ultrasonic vibrator is not adaptable to all these autoclavesterilization methods. Normally, autoclaving includes the cycle ofvacuum drawing, sterilizing, and drying steps. At times the autoclavingis urgently performed when the surgical apparatus is carelessly droppedonto a floor during surgery.

[0012] In such event, the vacuum drawing and sterilizing steps isperformed and the drying step is omitted to save time. By omitting thedrying step often causes steam that has entered the casing is notcompletely expelled therefrom, and, accordingly, the steam collects inthe form of drops of water in the casing, for example, in the casing ofa vibrator disclosed in Japanese Patent Publication No. Hei-106206. Ifultrasonic vibrations are started under this state, in a bolt-fastenedLangevin vibrator (transducer), the drops of water adhere betweenelectrodes between which a PZT (lead zirconate titanate) is disposed,and a short circuit is caused, thus decreasing the conversion efficiencyof the ultrasonic wave.

[0013] When autoclave sterilization is simply performed in a smallmedical institution, the autoclave sterilization often does not includethe drying step. Also, in this situation, as in the previous situation,drops of water collect in the casing, and, as a result, in abolt-fastened Langevin vibrator (transducer), the water adheres betweenelectrodes between which a PZT (lead zirconate titanate) is disposed,and a short circuit is caused, thus decreasing the conversion efficiencyof the ultrasonic wave.

[0014] The invention of U.S. Pat. No. 5,395,241 is a magnetostrictivevibrator (transducer), and therefore no problem occurs even if theinside thereof is intentionally subjected to autoclave sterilization.However, the magnetostrictive vibrator is inferior in washability. Fromthe viewpoint of the reduction in the size of a vibrator, abolt-fastened Langevin type vibrator (transducer) is greatly superiorthereto.

[0015] In the invention of Japanese Laid-open Patent Publication No. Hei10-127655, steam does not enter the inside of a vibrator when autoclavesterilization without a drying step is performed, and therefore theconversion-efficiency of ultrasonic vibrations does not decrease.However, there is a drawback in that smooth rotation cannot be madebecause an O-ring is used for a rotation slide portion, and there is aconcern that electric contact will become unreliable because an electriccontact portion is rotating. Additionally, there is a drawback in thatthe weight of the vibrator increases, and the outer diameter thereof isenlarged because the internal structure of the vibrator becomes complex.From the viewpoint of the versatility of the vibrator, the structure ofthe vibrator should be simple, of course.

[0016] In this type of ultrasonic surgical apparatus, the ultrasonicvibrator is driven at a resonance point in order to efficiently performthe surgery. Specifically, when the ultrasonic vibrator is driven, anoscillation frequency is controlled so that a phase difference between avoltage applied to the ultrasonic vibrator and a flowing current reacheszero by the use of PLL (phase-locked loop), and thereby the resonancepoint is pursued.

[0017] By the way, an equivalent circuit of the ultrasonic vibratorgenerally has a structure in which a braking condenser (brakingcapacitive component) is connected in parallel with a series resonancecircuit in which a coil L, a condenser C, and a resistor R are connectedin series. When a voltage is applied to such an ultrasonic vibrator, acurrent flows through both the braking condenser and the seriesresonance circuit. However, only the current flowing through the seriesresonance circuit of the two is converted into ultrasonic vibrations.Therefore, it is most efficient to drive the vibrator at the resonancepoint (mechanical resonance point) of the series resonance circuit.

[0018] Concerning a technique to drive the series resonance circuit atits resonance point (mechanical resonance point), many proposals havebeen offered heretofore. For example, in Japanese Patent No. 2,898,010,a composite capacitance value in a handpiece is kept constant, and acapacitive component (condenser) by which the composite capacitancevalue is equalized with an inductance of an inductive component(inductor) L of a driving power-supply unit, is connected in parallelwith a ultrasonic vibrator. In other words, the difference in the sizeof a capacity susceptance of a braking condenser, which various types ofultrasonic vibrators each possess, is compensated by the capacitivecomponent. According to this structure, the composite capacitance valueis kept constant even if the ultrasonic vibrators of the handpiecesconnected to the driving power-supply unit are of different types. Inother words, even if the ultrasonic vibrators that are different fromeach other in the size of the capacity susceptance of the brakingcondenser are each connected to one inductor, namely, a common drivingpower-supply unit, the capacity susceptance of the braking condenser isalways offset definitely (hereinafter, designated as “matching”). As aresult, a resonance frequency peculiar to the ultrasonic vibratorcoincides with a driving frequency of the driving power-supply unit.

[0019] However, if the ultrasonic vibrator and the capacitive component(condenser) are combined with each other, as described above, so as tobring about matching with respect to the driving power-supply unit,matching must be renewed by, for example, inspection or measurement wheneither the ultrasonic vibrator or the capacitive component (condenser)is repaired or replaced. This results in more complicated repairing andreplacing operations requiring a great deal of labor.

SUMMARY OF THE INVENTION

[0020] It is an object of the present invention to, in a bolt-fastenedLangevin type ultrasonic transducer, provide an ultrasonic vibrator thathas a very versatile, simple structure which does not include arotational structure, and is capable of infallibly preventing drops ofwater from entering the inside of the casing of the vibrator even ifautoclave sterilization without a drying process is performed.

[0021] It is another object of the present invention to provide anultrasonic vibrator capable of being easily replaced or repaired withoutperforming an adjustment for offsetting the capacity susceptance of abraking condenser of the ultrasonic vibrator with respect to theinductor of a driving power-supply unit.

[0022] An ultrasonic vibrator of the present invention is characterizedin that it comprises a transducer constructed by connecting a pluralityof vibrating elements for converting a driving current into vibrations;an amplitude increasing portion for increasing an amplitude of avibration of the transducer, the amplitude increasing portion having ahorn at a front side thereof and a flange-shaped fixing portion at abase side thereof, the transducer being connected to the flange shapedfixing portion side; a cover covering the transducer; asupporting/fixing member for supporting and fixing the flange-shapedfixing portion to the cover in an airtight state by interposing apacking between the flange-shaped fixing portion and the cover; a leadwire for supplying the driving current to the plurality of vibratingelements; a partition member, disposed at the base side of thetransducer, for defining a first chamber for passing the lead wire in anairtight state and containing the transducer in the cover in an airtightstate; a member, fitted to a base side of the cover in an airtightstate, for defining a second chamber for passing an electric powersupply cord in an airtight state and drawing the electric power supplycord into the cover between the partition member and the member; and aplug for connecting the electric power supply cord to an electric powerfor generation of the driving current.

[0023] Other objects and advantages of the present invention will becomesufficiently apparent from the detailed description given below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIGS. 1 to 5 show a first embodiment of the present invention;

[0025]FIG. 1 shows the external appearance of an ultrasonic vibrator;

[0026]FIG. 2 is an exploded view showing the decomposition/deployment ofa vibrator body of FIG. 1;

[0027]FIG. 3 is a sectional view of section 3-3 of the vibrator body ofFIG. 1;

[0028]FIG. 4 is a view showing the structure of a terminal provided in atransducer of FIG. 2, and

[0029]FIG. 5 shows the vibration distribution of the ultrasonic vibratorof FIG. 1 and the positional relationship of the inside of the vibratorbody.

[0030]FIG. 6 is an axially sectional view of a vibrator body accordingto a second embodiment of the present invention.

[0031] FIGS. 7 to 11 show a third embodiment of the present invention;FIG. 7 is a view showing the external appearance of the tip end of avibrator body;

[0032]FIG. 8 is a view showing the external appearance of the base endof the vibrator body of FIG. 7;

[0033]FIG. 9 is an exploded view showing the decomposition/deployment ofthe vibrator body of FIG. 7;

[0034]FIG. 10 is an axially sectional view of the vibrator body of FIG.7, and

[0035]FIG. 11 is an axially sectional view of a modification of thevibrator body of FIG. 7.

[0036] FIGS. 12 to 22 show a fourth embodiment of the present invention;

[0037]FIG. 12 is a perspective view of an ultrasonic vibrator unit;

[0038]FIG. 13 is a side sectional view of a handpiece of the ultrasonicvibrator unit of FIG. 12;

[0039]FIG. 14 is a cross sectional view along line 14-14 of FIG. 13;

[0040]FIG. 15 is a cross sectional view along line 15-15 of FIG. 13;

[0041]FIG. 16 is a cross sectional view along line 16-16 of FIG. 13;

[0042]FIG. 17 is a schematic electrical circuit diagram of theultrasonic vibrator unit of FIG. 12;

[0043]FIG. 18 is an exploded sectional view of the ultrasonic vibratorunit of FIG. 12;

[0044]FIG. 19 is a side sectional view of a modification of thehandpiece of the ultrasonic vibrator unit;

[0045]FIG. 20 is a side sectional view of a plug extending from thehandpiece of FIG. 19;

[0046]FIG. 21 is a perspective view showing another structure of theultrasonic vibrator, and

[0047]FIG. 22 is a perspective view showing the inside of a caseprovided in a cord of the ultrasonic vibrator of FIG. 21.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0048] Embodiments of the present invention will be describedhereinafter with reference to the attached drawings.

[0049] Embodiment 1

[0050] (Structure)

[0051] As shown in FIG. 1, an ultrasonic vibrator 1 according to thisembodiment includes: a plug 2 to be connected to a generator (not shown)that generates a driving current for allowing the ultrasonic vibrator 1to start ultrasonic vibrations; a cord 4 for sending the driving currentfrom the plug 2 to a vibrator body 3, and a waterproof cap 5 forpreventing water from entering the inside of the plug 2 when theultrasonic vibrator 1 is washed.

[0052]FIG. 2 is an exploded view of the vibrator body 3 of FIG. 1, andFIG. 3 shows section ABC of the vibrator body 3 of FIG. 1.

[0053] As shown in FIGS. 2 and 3, a transducer 10 that converts thedriving current sent from the generator (not shown) into ultrasonicvibrations is mounted in the vibrator body 3. An end of an electric wire11 whose coating is peeled off is fixed to the transducer 10 withsolder. The other end of wire 11 whose coating is also peeled off isfixed to a terminal 12 with solder.

[0054] Referring now to FIG. 4, an assembling method in the neighborhoodof the terminal 12 will be described. The terminal 12 is formed bybending a metallic plate, and by covering a part of the terminal 12, towhich the electric wire 11 is joined with solder 1 with aheat-shrinkable tube 12 a for insulation. The other end of the terminal12, to which the electric wire 11 is not joined with solder, has aterminal hole 12 b. An electrode 13 is passed through the terminal hole12 b, and, as shown in FIG. 2, through a hole 15 made in a partitionmember 14, and then a nut 16 is screwed onto a corresponding screw partof the electrode 13. As a result, the terminal 12 and the electrode 13are fastened with respect to the partition member 14. The electrode 13is provided with an O-ring 17 to maintain airtightness, as shown in FIG.4.

[0055] As shown in FIGS. 2 and 3, an electric wire 20, exposed bypeeling the coating from the cord 4, is fixed to the electrode 13 withsolder, and the coating edge of the cord 4 is fixed by a stop ring 22inside a heat-shrinkable tube 21. Thereby, the cord 4 is prevented frombeing carelessly detached from the vibrator body 3.

[0056] A connecting member 26 provided with O-rings 24 and 25 in pairs,for maintaining airtightness beforehand is bonded to a casing 23 inwhich the transducer 10 is incorporated. A rubber plate 29 is stuck ontoa side face of a flange 27 of the transducer 10, which faces theterminal 12, by means of an adhesive or the like. The rubber plate 29stuck onto the flange 27 corresponding to a nodal position can beremoved because heat or vibrations are seldom generated.

[0057] A set of the transducer 10, nut 16, partition member 14,electrode 13, terminal 12, and electric wire 11 is inserted into thecasing 23 from the side of the screw part 28 of the open end of thecasing 23. Then, the partition member 14 is inserted to be fit in thehole 30 of the connecting member 26. The hole 30 having awidth-across-flat part 31 engages with a partition member 14 a, therebypreventing the partition member 14 from rotating carelessly.

[0058] Thereafter, a packing 32 for securing airtightness is sandwichedbetween the partition member 14 and the connecting member 26, thepartition member 14 is then hung on an airtightness confirmation hole 33by the use of a jig (not shown) and is withdrawn into thewidth-across-flat part 31, and the screw part of the partition member 14is fixed with a nut 34. In order to fix the transducer 10 to the casing23, a packing 36 and a washer 37 for preventing the slippage of thepacking are inserted from the side of a horn 35 that increasesamplitude, and a fixing member 38 is screwed into the screw part 28.

[0059] Airtightness of the inside with respect to the outside is securedby O-rings 39 and 40, which are fastened to the fixing member 38beforehand, and the packing 36. When inspecting the airtightness, anairtightness confirmation connector is attached to the airtightnessconfirmation hole 33, and compressed air is sent in water, thusdetecting the presence of bubbles. After the inspection is completed, anairtight cap 42 with an O-ring 41 is screwed for maintaining theairtightness. Thereafter, the nut 16 and the electrode 13 are completelysealed up with a sealing agent 43 for the prevention of a short circuit.

[0060] The cord 4 is beforehand passed through an inner cap 51, an outercap 52, and an O-ring 53. The inner cap 51 with an O-ring 54 is screwedto the connecting member 26. The outer cap 52 is then attached to theouter periphery of the connecting member 26. Thereafter, a breakageprevention member 55 is screwed in the inner cap 51 so as to prevent thecord 4 from breaking, and thus the vibrator body 3 is completed. TheO-ring 25 and the O-ring 54 prevent water from entering a gap betweenthe inner cap 51 and the connecting member 26. The O-ring 53 preventswater from flowing from a gap between the cord 4 and the inner cap 51.

[0061]FIG. 5 shows the positional relationship between a vibrationdistribution 63 and the inside of the vibrator body 3. A node 64 of thevibration is located at the flange 27, an antinode 66 of the vibrationis located at the top of the horn 35, and an antinode 65 of thevibration is located at the rear end of the transducer 10. Each antinodeof the vibration coincides with a position of a ¼ wavelength of the node64.

[0062] (Operation)

[0063] After the ultrasonic vibrator 1 is used as the vibrator of anultrasonic coagulotomy instrument during surgery, the ultrasonicvibrator 1 is disconnected from the instrument and, with the waterproofcap 5 on the plug 2, is flushed to wash away dirt, such as body fluids,therefrom. After washing, the ultrasonic vibrator 1 is put into anautoclave sterilization device.

[0064] In the autoclave sterilization device, a pre-sterilizing step isperformed in which air in the device is withdrawn therefrom, andnegative pressure is applied. Thereafter, a sterilizing step isperformed in which a high-pressure steam is injected. As a result, thevibrator is sterilized. Normally, the vibrator is taken out of theautoclave sterilization device after the drying step subsequent to thesterilizing step. However, if sterilization is urgently needed duringsurgery, the drying step of is occasionally omitted.

[0065] If the drying step is omitted, it is impossible to completelyremove water resulting from a steam that has entered the inside of thevibrator body 3 through the inside of the cord 4 from the coating of thecord 4 and the plug 2.

[0066] However, the connecting member 26 and the partition member 14 areused as barrier members that make up the inside of the vibrator body 3.In addition, O-rings 17 and 41 are mounted on the packing 32, theelectrode 13, and the airtight cap 42. These prevent water from enteringa lumen 10 a (see FIG. 3) of the transducer 10. In addition, the sealingagent 43, by which the electrode 13 is sealed and insulated, prevents ashort circuit.

[0067] (Effect)

[0068] As mentioned above, in this embodiment, it is possible tonormally use the vibrator during surgery without causing an oscillatorydisorder of the vibrator and avoid the extension of surgery time, forexample, because water is prevented from entering the lumen 10 a of thetransducer 10 even if the autoclave sterilization in which the dryingstep is omitted is urgently performed during surgery, or the autoclavesterilization without the drying step is performed in a hospital havingonly an autoclave sterilization device that originally does not performa drying step.

[0069] No problem occurs even if each of the O-rings for maintainingairtightness is used as a pair of O-rings, in order to improve theairtightness.

[0070] Embodiment 2

[0071] Since a second embodiment is almost the same as the firstembodiment, different points alone will be described. The same referencecharacters are respectively given to the same constituents as in thefirst embodiment, and a description of them is omitted.

[0072] (Structure)

[0073] In a vibrator body 3 in this embodiment, the outer cap 8 in thefirst embodiment is replaced by an outer cap 71 provided with a terminalportion 72 for connecting an electric connection cord, as shown in FIG.6. The terminal portion 72 is screwed on the outer cap 71, andwatertightness is kept by O-rings 73 and 74. An end of an electric wire75 is joined to an internal end of the terminal portion 72 with solder,and the other end of the wire 75 is joined to the electrode 13 withsolder. The remainder of the structure is the same as in the firstembodiment.

[0074] (Operation)

[0075] In this embodiment, an electric knife can be used by connectingan electric-knife connecting cord to the terminal portion 72 when usingthe ultrasonic coagulotomy instrument. The remainder of the operation isthe same as in the first embodiment.

[0076] (Effect)

[0077] According to this embodiment, all that is required to use theelectric surgical knife is to connect the connecting cord to theterminal portion 72 of the vibrator, without using a probe for theknife, in a surgical operation, especially, in an endoscopic surgicaloperation. Therefore, in addition to the results achieved in the firstembodiment, another result can be obtained in that there is no need toexchange devices during surgery, thus allowing a surgeon to operatewithout such difficulties.

[0078] As in the first embodiment, no problem occurs even if each of theO-rings for maintaining airtightness is used as a pair of O-rings, inorder to improve the airtightness.

[0079] Embodiment 3

[0080] Since a third embodiment is almost the same as the firstembodiment, different points alone will be described. The same referencecharacters are respectively given to the same constituents as in thefirst embodiment, and a description of them is omitted.

[0081] (Structure)

[0082] In a vibrator body 3 in this embodiment, a horn 35 for increasingthe amplitude/vibration of the transducer 10 has a through hole 81extending along the axial center line of the vibrator body 3, as shownin FIG. 7. And, as shown in FIG. 8, the member of the horn 35 isconstructed as the same constituent as a tubular member 82 that extendsto the rear end of the transducer 10. The through hole 81 is a ductcoaxial with a suction duct 98 which is a through hole of a tubularmouthpiece 99 disposed at the rear end of the vibrator body 3.

[0083] The structure of the vibrator body 3 in this embodiment will bedescribed hereinafter with reference to FIGS. 9 and 10.

[0084] A through hole 92 with an O-ring 91 is made in the center of apartition member 90 in this embodiment instead of the partition member14 shown in the first embodiment. A tubular member 82 is inserted in thethrough hole 92.

[0085] In this state, a nut 16, an electrode 13, a transducer 10, and apartition member 90 are inserted into the inside of a casing 23, as inthe first embodiment, and are fastened by a nut 34. An inner cap 93 inthis embodiment is fastened to a connecting member 26 by means of ascrew (not shown) instead of the inner cap 51 in the first embodiment. Apipe 96 having a tubular duct 95 provided with an O-ring 94 is thenscrewed on the inner cap 93, and is fixedly inserted into the throughhole 92 of the partition member 90. The suction mouthpiece 99 having thesuction duct 98 provided with an O-ring 97 is screwed onto an outer cap100 in this embodiment instead of the outer cap 52 in the firstembodiment, and the outer cap 100 is fastened to the connecting member26. The cord 4 and the breakage prevention member 55 are screwed andfixed at an eccentric position with respect to the outer cap 100. Theother structure is the same as in the first embodiment.

[0086] (Operation)

[0087] In addition to the operation in the first embodiment, in thisembodiment, the vibrator body 3 has the through hole, and, accordingly,when a suction tube (not shown), which is combined with an outsidesuction apparatus, is connected to the suction mouthpiece 99, a liquidabsorbed from the tip of a perforated probe (not shown) of the horn 35can flow to the suction tube via the through hole 81, the pipe 96, andthe suction duct 98, and can drain into the outside. Alternatively, whena tube for supplying water is attached to the suction mouthpiece 99,physiological saline, for example, can flow to the tip of the perforatedprobe (not shown) through the suction duct 98, the pipe 96, and thethrough hole 81, and thus can be supplied to a surgical region.

[0088] (Effect)

[0089] According to this embodiment, the same effect as in the firstembodiment can be obtained even if the vibrator is used as a vibratorunit of the ultrasonic suction apparatus. The ultrasonic suctionapparatus can suck vital tissues in the form of emulsion and can suckperipheral tissues while leaving vessels in accordance with thefunction-of selectiveness of tissues, and therefore time the requiredfor surgery can be shortened. In addition, since physiological salineetc. can be supplied to a surgical region when necessary, surgery can beperformed smoothly.

[0090] A modification of the vibrator body 3 shown in FIG. 10 can beperformed as shown in FIG. 11. A feature different from that of FIG. 10is that the O-ring 91 for maintaining airtightness is situated at thenodal position of the vibration as a member 82A extending the tubularmember 82. As a result, frictional heat caused by vibrations is noteasily generated because of the nodal position of the vibration even ifultrasonic oscillation occurs, and the rise of temperature issuppressed.

[0091] As in the first embodiment, no problem occurs even if each of theO-rings for maintaining airtightness is used as a pair of O-rings, inorder to improve the airtightness.

[0092] Embodiment 4

[0093]FIG. 17 schematically shows the structure of the main part of anelectric circuit of an ultrasonic treatment apparatus. AS shown in thefigure, either an ultrasonic vibrator unit 101A or 101B according to afourth embodiment of the present invention is connected to a main body(i.e., driving power-supply unit) 150 of the ultrasonic treatmentapparatus through connecting pins 140A and 140B of a plug 103, describedlater (see FIG. 12).

[0094] The ultrasonic vibrator unit 101A (101B) is provided with atransducer 117A (117B) having a braking capacitor (braking capacitivecomponent) C1 (C2). A capacitor (capacitive component) 123A (123B) isconnected in parallel with the transducer 117A (117B).

[0095] The main body 150 of the ultrasonic treatment apparatus isprovided with a driving circuit 151. The driving circuit 151 that isconnected to the connecting pins 140A and 140B of the plug 103 drivesthe transducer 117A (117B) of the ultrasonic vibrator unit 101A (1B)connected to the main body 150 at the mechanical resonance pointthereof.

[0096] An inductor (inductive component) L is mounted in the main body150 of the ultrasonic treatment apparatus. The inductor L is placedbetween the connecting pins 140A and 140B, and is arranged to beconnected in parallel with the transducer 117A (117B) of the ultrasonicvibrator unit 101A (101B) connected to the main body 150. The inductor Lis provided to offset a composite capacitance value (i.e., sum ofcapacity susceptance) between the braking capacitor C1 (C2) and thecapacitor 123A (123B) in the ultrasonic vibrator unit 101A (101B).

[0097] The capacitor 123A (123B) as the capacitive component is providedto keep the composite capacitance value in the ultrasonic vibrator unit101A (101B) constant and to equalize the composite capacitance valuewith the inductance of the inductor L. In other words, the capacitor123A (123B) functions to compensate the size of the capacity susceptanceof the braking capacitor C1 (C2) which depends on the kind of thetransducer 117A (117B).

[0098] In this embodiment, when the ultrasonic vibrator unit 101A isconnected to the main body 150, the driving circuit 151 and thetransducer 117A are connected to each other through the connecting pins140A and 140B. Additionally, the inductor L, the braking capacitor C1,and the capacitor 123A are connected in parallel with each other throughthe connecting pins 140A and 140B. This connection makes it possible tooffset a composite capacitance value between the braking capacitor C1and the capacitor 123A by the inductance of the inductor L. That is, thecomposite capacitance value therebetween is equalized with theinductance of the inductor L. As a result, the capacity susceptance ofthe braking capacitor C1 of the transducer 117A is infallibly offset.Accordingly, the transducer 117A of the ultrasonic vibrator unit 101Acan be reliably driven at the mechanical resonance point thereof.Therefore, surgical operations, such as destruction of a calculus orremoval of a tumor, can be efficiently performed by the ultrasonicvibrator unit 101A.

[0099] Even if the ultrasonic vibrator unit 1B is connected to the mainbody 150, the composite capacitance value will be offset by theinductance of the inductor L.

[0100] As described above, in this embodiment, the difference in thesize of the capacity susceptance of the braking capacitor, which varioustypes of transducers individually have, is designed to be offset by thecapacitor 123A (123B). That is, even if the transducers of theultrasonic vibrator units connected to the main body 150 are differentin kind from each other, the composite capacitance value thereof isdesigned to be kept constant. Therefore, even when transducers that aredifferent in the size of the capacity susceptance of the brakingcapacitor are driven, the capacity susceptance of the braking capacitorcan be infallibly offset by one kind of inductor. As a result, varioustypes of transducers can be reliably driven at the mechanical resonancepoint thereof.

[0101] The mechanical structure of the ultrasonic vibrator unit 101A(101B) is shown in FIGS. 12 to 16.

[0102] Referring to FIG. 12, a handpiece cord 104 extends from the baseend of the vibrator unit 101A (101B), and a plug 103 is joined to theend of the handpiece cord 104. The plug 103 has connecting pins 140A and140B which are to be electrically connected to a connector (not shown)of the main body 150 of the ultrasonic treatment apparatus. A rib 103Aprojects from the outer surface of the plug 103. The rib 103A is engagedwith the connector of the main body 150 and serves as an indicator fordetermining the direction in which the plug 103 is connected to the mainbody 150. The plug 103 additionally has a watertight cap 105 formaintaining watertightness when not used.

[0103] As shown in FIG. 13, the vibrator unit 101A (101B) is constructedas a handpiece 102. The handpiece 102 has a cylindrical cover used as ahandgrip. The cover consists of a front case 107A and a rear case 107B,each detachable. The front case 107A includes a transducer unit 145A(145B) constructed by integrally assembling the transducer 117A (117B)and the capacitor 123A (123B). (See FIGS. 17 and 18 in addition to FIG.13).

[0104] The transducer 117A (117B) has a vibrator body including aplurality of piezoelectric elements 119, and a horn 147, connected tothe vibrator body, for amplifying an ultrasonic vibration generated inthe vibrator body and increasing the amplitude. The tip of the horn 147has a female screw 190 to which a probe unit, not shown, is fastened. Aflange 118 projects from the base of the horn 47.

[0105] The transducer unit 145A (145B) is supported inside the frontcase 107A by means of a supporting nut 111 screwed into the top of thefront case 107A. Specifically, the transducer unit 145A (145B) issupported inside the front case 107A such that the flange 118 of thehorn 147 is sandwiched between a supporting portion 155 projecting fromthe inner surface of the front case 107A and the supporting nut 111. Inthis embodiment, a first supporting rubber 116 for absorbing vibrationsis placed between the supporting portion 155 and the flange 118.Additionally, a second supporting rubber 115 and a washer 114 that serveto absorb vibrations and maintain watertightness and airtightness areplaced between the flange 118 and the supporting nut 111.

[0106] A cylindrical connection member 159A is screwed in a screwportion 163 formed in the inner surface of the top of the front case107A, and a cylindrical receiving member 159B is screwed in the innersurface of the connection member 159A. These members 159A and 159B makeup a connection portion 159 that connects the vibrator unit 101A (101B)to a handle unit, not shown. Specifically, an engagement ring 108 (seeFIG. 14) that was a C-shaped section is disposed in an annular groove109 formed on the receiving member 159B, and the engagement ring 108 iselastically engaged with an engagement groove of the handle unit, andthereby the vibrator unit 101A (101B) is connected to the handle unit.

[0107] An adjusting nut 110 is screwed on the outer surface of theconnection member 159A screwed to the screw portion 163 of the frontcase 107A, with the adjusting nut 110 in contact with the top of thefront case 107A. When the adjusting nut 110 is rotated, the connectionmember 159A is axially moved with respect to the front case 107A, andthe axial position of the connection portion 159 is adjusted.

[0108] An O-ring 112 is interposed between the supporting nut 111 andthe horn 147. The O-ring 112 that secures watertightness andairtightness supports and positions the horn 147 at the center of thefront case 107A. Additionally, an O-ring 113 that secures watertightnessand airtightness is interposed between the supporting nut 111 and thefront case 107A.

[0109] Each of the piezoelectric elements 119 that is a constituent ofthe vibrator body is arranged to be interposed between electrode plates120 and 120. An electric wire 122 for supplying a current is united tothe electrode plate 120 with solder. In this embodiment, when a currentis caused to flow between the electrode plates 120 through the electricwire 122, the piezoelectric element 119 expands and contracts, thusgenerating ultrasonic vibrations.

[0110] The electric wire 122 extends to the inside of a second heatshrinkable tube 125 located on the base end side of the front case 107Athrough a first heat shrinkable, electrically nonconductive tube 121.Legs 166,166 of the capacitor 123A (123B) disposed on the base end sideof the transducer 117A (117B) extend to the inside of the second heatshrinkable tube 125, and are soldered to terminals 124, 124,respectively, together with the electric wire 122.

[0111] The cylindrical connection member 139 is fitted in the innersurface of the base end of the front case 107A. In this embodiment, anO-ring 126 for securing watertightness and airtightness is interposedbetween the front case 107A and the connecting member 139. The base endof the connecting member 139 projects from an opening on the base endside of the front case 107A. The top of a cylindrical inner cap 134 isfixed to the base end of the projecting connecting member 139 by meansof a screw 144. The rear case 107B is screwed on a screw portion 134 aformed in the outer peripheral surface of the inner cap 134 so as tocover the inner cap 134 from the outside. In this embodiment, an O-ring141 for securing watertightness and airtightness is interposed betweenthe inner cap 134 and the rear case 107B.

[0112] In a state where the rear case 107B has been sufficiently screwedon the screw portion 134 a as shown in FIG. 13, the top side of the rearcase 107B is pressed to be brought in contact with the base side of thefront case 107A, with the packing 128 therebetween. The packing 128 iscompressed by the pressure of the top side of the rear case 107B and thebase side of the front case 107A, thereby securing watertightness andairtightness between the cases 107A and 107B.

[0113] The handpiece cord 104 is detachably connected to the base end ofthe inner cap 134. Specifically, a connection tube 192, fitted on theouter peripheral surface of the base end of the handpiece cord 104, isscrewed in the inner cap 134. In this embodiment, an O-ring 142 forsecuring watertightness and airtightness is interposed between the innercap 134 and the connection tube 192. A cylindrical breakage preventionmember 143 is fixed to the connection tube 192. The breakage preventionmember 143 is fit on the peripheral surface of the end of the handpiececord 104, and prevents breakage of the connected part of the handpiececord 104.

[0114] The end of the handpiece cord 104 extends through the connectiontube 192, and projects in the inner cap 134 through an opening 181 ofthe base end of the inner cap 134. A detachment preventing member 135whose diameter is larger than the inner diameter of the opening 181 ofthe inner cap 134 is attached to the end of the handpiece cord 104.Accordingly, the handpiece cord 104 will not come out of the inner cap134 because the detachment preventing member 135 is bumped against theinner surface of the inner cap 134 when the handpiece cord 104 iscarelessly pulled to the operator's side.

[0115] A partition 137 by which the handpiece 102 is divided into twowatertight/airtight chambers 136,138 is unrotatably attached to theconnecting member 139 fitted in the front case 107A. Specifically, asclearly shown in FIG. 16, the partition 137 has a noncircular section,and is inserted into a noncircular fixing hole 139 a formed by an innerprojection 171 of the top end of the connecting member 139, and thus isincapable of rotating. The partition 137 additionally has a flange 173on the end of the side facing the capacitor 123A (123B), and has a screwportion 177 on the outer surface of the end projecting to the inner cap134. A nut 130 is screwed onto the screw portion 177 of the flange,thereby pressing the flange 173 to the inner projection 171, and thepartition 137 is fastened to the connecting member 139. In other words,the partition 137 is fastened to the connecting member 139 bysandwiching the inner projection 171 between the flange 173 and the nut130 screwed on the screw portion 177. Thus, the partition 137 dividesthe inside of the handpiece 102 into a front chamber 138 of the frontcase 107A in which the transducer unit 145A (145B) is disposed and arear chamber 136 of the rear case 107B into which the handpiece cord 104is drawn. Packings 127, 127 for watertightness and airtightness are eachinterposed between the nut 130 and the inner projection 171 and betweenthe flange 173 and the inner projection 171.

[0116] The partition 137 has two through-holes 137 a and 137 b. Anelectrode 129 is passed through each of the through-holes 137 a and 137b. The electrode 129 has a rectangular flange 129 a on the end of theside facing the capacitor 123A (123B), and has a screw portion 181 onthe outer surface of the end projecting to the inner cap 134. A nut 132is screwed onto the screw portion 181, thereby pressing the flange 129 ato the end side of the partition 137, and the electrode 129 is fixedwith respect to the partition 137. In other words, the electrode 129 isfixed with respect to the partition 137 by sandwiching the partition 137between the flange 129 a and the nut 132 screwed on the screw portion181. The electrode 129 is electrically connected to the terminal 124 bysandwiching the terminal 124 between the end side of the flange 129 aand the partition 137. The electrode 129 is engaged with a long groove167 formed in the end side of the partition 137, and is stopped fromrotating with respect to the partition 137. O-rings 197 forwatertightness and airtightness are each interposed between theelectrode 129 and the inner surface of the through-hole 137 a, andbetween the electrode 129 and the inner surface of the through-hole 137b of the partition 137.

[0117] Two electric lines 172, 172 are led from the opening of the endof the handpiece cord 104 projecting to the inner cap 134. A pinterminal 131 is electrically connected to the end of the line 172. Thepin terminal 131 is subjected to press-fitting and is fixed to terminalconnection hole 188 formed in the end of the electrode 129 that projectsto the inner cap 134 side. A connected part between the pin terminal 131and the electric line 172 is coated with a heat shrinkable, electricallynonconductive tube 195.

[0118] The rear chamber 136 is almost completely filled with a sealingagent 133. Accordingly, when autoclave sterilization, for example, isperformed, high-pressure steam is prevented from entering the frontchamber 138 where the transducer unit 145A (145B) is disposed.

[0119] In the thus constructed ultrasonic vibrator units 101A, 101B, thetransducer unit 145A (145B) as a single unit can be easily taken out ofthe handpiece 102 in such a way that the connection portion 159 and thesupporting nut 111 are detached from the front case 107A, the rear case107B and the screw 144 are then detached from the inner cap 134, and theconnection between the connecting member 139 and the inner cap 134 isreleased, and thereby the nut 130 is detached, as shown in FIG. 18.

[0120] As mentioned above, in the ultrasonic vibrator units 101A, 101B,the combination of the capacitor 123A (123B) and the transducer 117A(117B), in which matching has been beforehand applied to the main body150, is constructed as a single unit 145A (145B), and the unit 145A(145B) is arranged to be freely attached to or detached from thehandpiece.

[0121] Therefore, when either the transducer 117A (117B) or thecapacitor 123A (123B) breaks down, there is no need of making a matchingadjustment to the main body 150 (i.e., the retrying of matching by e.g.inspection or measurement) if the transducer unit 145A (145B) itself isexchanged. Thus, they can be easily repaired and exchanged.

[0122] Another example of an embodiment for realizing the size reductionof the handpiece is shown in FIGS. 19 and 20. As shown in FIG. 19, onlythe transducer 117A (117B) is disposed in the handpiece 102, and, asshown in FIG. 20, the capacitor 123A (123B) is disposed in the plug 103.Therefore, the handpiece can be reduced in size by a space where thecapacitor 123A (123B) is disposed. In FIG. 19, the same referencecharacters are given to the same constituents, respectively, as in theprevious embodiments. The size reduction of the handpiece 102 can berealized also by disposing the capacitor 123A (123B) on the way of thehandpiece cord 104, as shown in FIGS. 21 and 22. In this structure, thecapacitor 123A (123B) is directly connected to the electric line 172 inthe handpiece cord 104, and is contained in the case 162. In order toposition the case 162, a detachment preventing member 135A that projectsin the case 162 is provided in the end of the handpiece cord 104.

[0123] In this invention, it is apparent that various embodiments inwide scope can be carried out according to the present invention withoutdeparting from the spirit and scope thereof. The present invention isnot limited by a specific embodiment thereof, except that it is limitedby the attached claims.

What is claimed is:
 1. ultrasonic vibrator comprising: a transducerhaving a braking capacity component constructed by connecting aplurality of vibrating elements for converting a driving current intovibrations; a capacitive component portion connected in parallel withsaid transducer; a plug detachably connected to an ultrasonic drivegenerating portion for generating said driving current; and an electricpower supply cord for supplying said driving current from said plug tosaid transducer; wherein a composite capacity value of said brakingcapacity component and a capacity component of said capacitive componentportion is turned into a capacitive component value that offsets aninductive component disposed in said ultrasonic drive generatingportion, and said capacitive component portion is disposed in a covercovering said transducer.
 2. The ultrasonic vibrator of claim 1, whereinsaid transducer and said capacitive component portion are made a singleunit.
 3. An ultrasonic vibrator comprising: a transducer having abraking capacity component constructed by connecting a plurality ofvibrating elements for converting a driving current into vibrations; acapacitive component portion connected in parallel with said transducer;a plug detachably connected to an ultrasonic drive generating portionfor generating said driving current; and an electric power supply cordfor supplying said driving current from said plug to said transducer;wherein a composite capacity value of said braking capacity componentand a capacity component of said capacitive component portion is turnedinto a capacitive component value that offsets an inductive componentdisposed in said ultrasonic drive generating portion, and saidcapacitive component portion is disposed in an inside of said plug. 4.An ultrasonic vibrator comprising: a transducer having a brakingcapacity component constructed by connecting a plurality of vibratingelements for converting a driving current into vibrations; a capacitivecomponent portion connected in parallel with said transducer; a plugdetachably connected to an ultrasonic drive generating portion forgenerating said driving current; and an electric power supply cord forsupplying said driving current from said plug to said transducer;wherein, a composite capacity value of said braking capacity componentand a capacity component of said capacitive component portion is turnedinto a capacitive component value that offsets an inductive componentdisposed in said ultrasonic drive generating portion, and saidcapacitive component portion is disposed in apart of said electric powersupply cord.